From fc85e6cb050aa93cca3c67784a0b160e64ed3cec Mon Sep 17 00:00:00 2001
From: Adam James <adam.james@transitiv.co.uk>
Date: Thu, 1 Feb 2024 11:57:12 +0000
Subject: [PATCH] Add Graphite Web HTTP request timeout option

If the Graphite Web server is unreachable, all requests for frontend
pages containing graphs hang until the backend HTTP request times out,
resulting in a very poor UX.

The Guzzle documentation states that the default behaviour is to wait
indefinitely, however in our testing the cURL handler has an internal
default of 30 seconds:

https://docs.guzzlephp.org/en/stable/request-options.html#timeout

This commit makes the HTTP request timeout configurable and sets a
reasonable default of 10 seconds.
---
 application/forms/Config/BackendForm.php      | 10 +++++
 library/Graphite/Graphing/GraphingTrait.php   |  1 +
 .../Graphite/Graphing/GraphiteWebClient.php   | 40 +++++++++++++++++--
 3 files changed, 48 insertions(+), 3 deletions(-)

diff --git a/application/forms/Config/BackendForm.php b/application/forms/Config/BackendForm.php
index 90e0af2..fb3970b 100644
--- a/application/forms/Config/BackendForm.php
+++ b/application/forms/Config/BackendForm.php
@@ -53,6 +53,16 @@ class BackendForm extends ConfigForm
                     'label'         => $this->translate('Connect insecurely'),
                     'description'   => $this->translate('Check this to not verify the remote\'s TLS certificate')
                 ]
+            ],
+            [
+                'number',
+                'graphite_timeout',
+                [
+                    'label'         => $this->translate('Request timeout'),
+                    'description'   => $this->translate('The timeout for HTTP requests to Graphite Web'),
+                    'min'           => 0,
+                    'placeholder'   => 10
+                ]
             ]
         ]);
     }
diff --git a/library/Graphite/Graphing/GraphingTrait.php b/library/Graphite/Graphing/GraphingTrait.php
index a1c1cdc..463c61c 100644
--- a/library/Graphite/Graphing/GraphingTrait.php
+++ b/library/Graphite/Graphing/GraphingTrait.php
@@ -73,6 +73,7 @@ trait GraphingTrait
                     ->setUser($graphite->user)
                     ->setPassword($graphite->password)
                     ->setInsecure((bool) $graphite->insecure)
+                    ->setTimeout(isset($graphite->timeout) ? intval($graphite->timeout) : 10)
             );
         }
 
diff --git a/library/Graphite/Graphing/GraphiteWebClient.php b/library/Graphite/Graphing/GraphiteWebClient.php
index 982a2af..9d8196a 100644
--- a/library/Graphite/Graphing/GraphiteWebClient.php
+++ b/library/Graphite/Graphing/GraphiteWebClient.php
@@ -40,6 +40,13 @@ class GraphiteWebClient
      */
     protected $insecure = false;
 
+    /**
+     * Timeout for every Graphite Web HTTP request
+     *
+     * @var ?int
+     */
+    protected $timeout;
+
     /**
      * HTTP client
      *
@@ -79,9 +86,12 @@ class GraphiteWebClient
         // TODO(ak): keep connections alive (TCP handshakes are a bit expensive and TLS handshakes are very expensive)
         return (string) $this->httpClient->send(
             new Request($method, $this->completeUrl($url)->getAbsoluteUrl(), $headers, $body),
-            ['curl' => [
-                CURLOPT_SSL_VERIFYPEER => ! $this->insecure
-            ]]
+            [
+                'curl' => [
+                    CURLOPT_SSL_VERIFYPEER => ! $this->insecure
+                ],
+                'timeout' => $this->timeout ?? 10
+            ]
         )->getBody();
     }
 
@@ -195,4 +205,28 @@ class GraphiteWebClient
 
         return $this;
     }
+
+    /**
+     * Get the HTTP request timeout
+     *
+     * @return ?int
+     */
+    public function getTimeout(): ?int
+    {
+        return $this->timeout;
+    }
+
+    /**
+     * Set the HTTP request timeout
+     *
+     * @param ?int $timeout
+     *
+     * @return $this
+     */
+    public function setTimeout(?int $timeout): self
+    {
+        $this->timeout = $timeout;
+
+        return $this;
+    }
 }